Fuel supplying pump for internal combustion engines of the airless fuel injection type



Aug. 15, 1933. J Q GRQFF 1,922,539

FUEL SUPPLYING PUMP FOR INTERNAL COMBUSTION ENGINES OF THE AIRLESS FUELINJECTION TYPE Filed Dec. 14. 1929 H}: a 2h; 22

E l6 1 'W 5 l J L INVENTOR ATTORNEYS Patented Aug. 15, 1933 UNITEDSTATES PATENT OFFICE Joseph' C. Groff, Allentown, Pa.

Application December 14, 1929 Serial No. 414,016

14 Claims.

The present invention relates to pumps for supplying and injectingliquid fuel into the combustion spaces of internal combustion engines ofthe fuel injection type, though more particularly to pumps for effectingso called solid or airless-injection of the fuel.

In internal combustion engines of the fuel injection type it isnecessary and desirable that certain individual combustion regulatingfactors, .which determine operation of the engine, be respectivelysubject to independent control and adjustment. First, provision shouldbe made for varying the quantity of fuel supplied to the power cylinderper cycle in accordance with the load requirements. Second, provisionshould be made to change or adjust the timing of injection commencementin order to secure the most efficient operation at various engine speedsand when using different grades of fuel. Third, provision should be madeto change the velocity of the fuel as supplied to the injection valve bythe fuel pump in order to achieve the utmost efficiency of fuelinjection and attendant combustion for all of the various conditions ofengine operation including that of starting from the cold condition.

Heretofore constructions have been devised in which so-called by-passvalves have been used auxiliary to the pump itself for accomplishingcertain of the above results. In some constructions variation in thequantity of fuel supplied per cycle has been effected without the use ofa by-pass valve and this has been accomplished by varying the amplitudeof stroke of the fuel pump plunger. However, the constructions employedheretofore brought about an objectionable change in the velocity withwhich the fuel was injected when the quantity of fuel supplied was sovaried.

The present invention has for its objects the provision of a novelconstruction which will permit the three control adjustments abovementioned to be accomplished without employing a by-pass valve for anyof the controls and particularly the first and to also provide aconstruction in which the relation and disposition of the parts is suchthat each control may be adjusted independently of and Without affectingadjustment of another control.

A further object of the present invention resides in the provision of apump construction which will embody simplicity of mechanism and whichwill afford quietness and reliability in operation.

Other and more detailed objects and advantages of the present inventionwill be hereinafter pointed out in the accompanying specification andclaims, and shown in the drawing which by way of illustration, showpreferred embodiments of my invention.

In the drawing:

Figure 1 is a transverse sectional elevation which illustratesdiagrammatically the principle and arrangement of the linkage and partsof a fuel injecting pump embodying my present invention, particularlyfor engines which need not be reversed and which develop relativelysmall horsepower per cylinder at rather high speed. It is takensubstantially on line 1-1 in Fig. 2 facing in the direction of thearrows and shows the arrangement of the parts just prior to the instantof commencement of fuel injection.

Fig. 2 is a detailed sectional View taken substantially on line 2-2 inFig. 1 facing in the direction of the arrows. For the sake of clearerillustration certain of the parts appearing in Fig. 1 have been omittedin Fig. 2.

25 is a fuel pumping plunger which is preferably of the differentialtype and adapted to reciprocate Within the differential cylinder member40 with a close sliding fit and to effect a pressure tight jointtherewith. Upon any downward movement of the plunger 25 the annularpumping chamber 39 is supplied and filled with liquid fuel via supplypipe 34, automatic inlet valve 35, and conduit 36. Preferably the fuelsupplied via pipe 34 should exist therein under a relatively low butpositive pressure in order to eliminate any tendency for the pumpchamber 39 to become air-bound. This may be accomplished by any ofvarious known means such as a supply pump of the constant pressure typeor a gravity feed tank not shown in the drawing.

Upon completion of any downward movement of plunger 25, and afterchamber 39 and conduit 36 have been completely filled with fuel, flow offuel via inlet valve 35 ceases and said valve automatically closes.

Upon and by any subsequent upward movement of plunger 25, fuel isdisplaced thereby and forced out of the annular space 39 and is injectedinto the combustion space of the engine via conduit 36, automaticnon-return discharge valve 37, discharge pipe 38 and any suitable knowninjecting valve of the airless automatic spring loaded type (not shownin the drawing).

Plunger 25 and its crosshead 27 are arranged to be given reciprocatingmovement by means of link 21 which is pivotally connected to saidcrosshead and plunger at one end by pin 24, and

which carries any suitable bearing member, h as roller 22, at its otherend. Link 21 and its roller bearing 22 is adapted to be oscillated,about pin 24 as a pivot point, through any desired angle, asillustratively denoted by arc 28, which is always substantially constantin amplitude of swing.

Oscillation of link 21 and its roller bearing 22 may be effected in anysuitable known manner such as by means of connecting rod 20 andcranklike operating member 19 which preferably rotates in the directionindicated by arrow 23. It should be understood that crank 19 is drivenby the engine and would always be in fixed time relation thereto. In thecase of a two-cycle engine, the fuel pump operating crank 19 wouldrotate at the same speed as the engine crankshaft. However, in the caseof a four cycle engine crank 19 would be driven so as to rotate onlyhalf as fast as the engine crankshaft. This drive of 19 from the enginemay be accomplished in any suitable known fashion such as by gearing orchain drive not shown in the drawing.

The roller bearing 22 at the lower end of link 21 is adapted to rollablycontact with a guiding member 9 which presents a bearing surface havinga concave curvature in the shape of an arc of a circle the radius ofwhich is equal to the length of link 21 between center 24 and thecontacting surface of roller 22, (i. e. equal to length of link 21between its centers plus the radius of roller 22). Also, the center ofcurvature of guiding member 9 is located on the straight path traversedby pivot point 24 as plunger 25 is given reciprocating movement, andwith the parts as shown in Fig. 1 the aforesaid center of curvature islocated at point 24.

Plunger 25 and roller 22 always tend to return downwards and to exert adownward pressure upon the driving parts with which they contact byvirtue of compression spring 41.

The quantity of fuel delivered and injected by the pump is dependentupon and determined by the amplitude of movement of plunger 25.According to the present invention this is accomplished by interposingan adjustable camlike member 14 which acts to guide roller 22 and 'todisplace it upwards away from the aforementioned guiding member 9. Theamplitude of such upward displacement of roller 22 may be adjusted asdesired by altering the angular position of control lever 18 which actsthrough shaft 16 to depress or elevate the position of the eccentricallymounted supporting member '7 and of interposer member 14 as well,through any desired vertical range 17. Thus, the amplitude of upwardpumping movement of roller 22 and of plunger 25 would be at a maximum,for maximum engine load, such as illustratively indicated by verticalrange 26, fractionally less at reduced engine loads and nothing for thecondition wherein the engine would be coasting to a standstill with itspower cut off. With regard to this last named condition, it should beunderstood that interposer member 14-12 will have been sufficientlydepressed below the bearing surface of guiding member 9 so as to permitroller 22 to traverse a circular path having its center always locatedand fixed at point 24 (for the operating condition just outlined) and totherefore impart no upward movement to plunger 25.

The timing of injection commencement for any given adjustment ofquantity of fuel and of the velocity with which it is supplied andinjected,

may have its adjustment changed by advancing or retarding the positionof interposer 14-12 horizontally (in Fig. 1) with respect to thedirection of oscillation of link 21 and its roller bearing 22. This maybe done in any suitable manner such as by means of control lever 31which acts through eccentric shaft 3 to move point 8 of supportingmember 7 to the left or right through a substantially horizontal rangeas illustratively denoted by 32. In Fig. 1, movement of point 8, and ofinterposer 14, to the left would result in advanced timing whilemovement to the right of its indicated position would result in delayedtiming of injection commencement.

With regard to the velocity or rate at which fuel is supplied by thepump to the injecting valve (not shown in drawing) it should beunderstood that such velocity is dependent upon and determined by thevelocity of upward movement of plunger 25. Adjustable change of thevelocity of upward pumping movement of plunger 25 is effected in thenovel manner shown in Fig. 1 by changeably adjusting the degree of tiltor slope of the guiding and displacing surface 12 of interposer member14 with respect to the horizontal and to the guiding member 9. That isto say, the velocity of upward pumping movement of roller 22 and ofplunger 25 will increase as the angle of slope of 12 is increased withrespect to the horizontal and vice versa. Referring to Fig. 1,adjustable variation of the degree of tilt of 12 is effected by angularmovement of control lever 10 which acts to bodily displace theeccentrically mounted rod 15 through a range illustratively denoted by13.

With the various parts occupying the positions shown in Fig. 1, roller22 is in rolling contact with the curved guiding surface of member 9.and subsequent movement of roller 22 to the right will contact it withthe straight sloping surface 12 of interposer member 14, and will causeit to be displaced upwardly away from said guiding member 9 until itreaches the top end portion of said sloping surface 12. Upon roller 22swinging further to the right and upon its passing over theaforementioned top end portion of 12, said roller 22 will contact with asecondary guiding portion 5 of interposer 14. This secondary portion 5affords a guiding surface for roller 22 to contact with, which has aconcave curvature of the same length radius 30 as guiding member 9, andwhich always has its center of curvature located substantially on thestraight path traversed by the reciprocating point of pivotal connection24 between link 21 and plunger 25.

Any suitable known means, such as the compensating linkage completed bylink 6, may be employed to automatically position the aforementionedsecondary portion 5, about its point of pivotal mounting 4 on interposer14, so that its instantaneous center of curvature always liessubstantially on the aforementioned straight path traversed by 24,regardless of what control adjusting movements are given to saidinterposer 14.

I prefer to restrict contacting of roller 22 with the sloped displacingsurface 12 of interposer 14 to within the central and substantiallymiddle third portion 29 of the total angle 28 through which link 21 andits roller bearing 22 oscillate. In other words, I prefer to restrictfuel pumping action to substantially the central third zone of the rangeof oscillation, for in this zone there results the most uniform rate ofswing of link 21 by crank 19 to thus secure desirable lessening of thefluctuations in rate of swing as associated with the harmic motionaction of said crank.

Accordingly, with my novel construction each swing of oscillating link21 and roller 22 from extreme left to extreme right, as determined bycrank 19 and as indicated in Fig. 1 by the dotted lined portions ofroller 22, is made up of three phases of movement of roller 22 andplunger 25. First, roller 22 rollably contacts with the curved guidingmember 9 during which period (substantially one-third of total angle ofswing of link 21) no upward pumping movement of plunger 25 takes place.Secondly, roller 22 subsequently contacts with the sloped displacingsurface 12' of interposer 14 and during such contact (lasting oversubstantially the central or following one-third of the total angle ofswing of link 21 depending upon the engine load) there results upwardpumping movement of plunger 25. Third, and lastly, roller 22 overrunsthe sloped displacing surface 12 and rollably contacts with the adjacentand secondary curved guiding portion 5, at which instant upward movementof plunger 25 ceases to have thus completed a fuel pumping stroke. Uponthe return swing of link 21 and roller 22, from right to left of Fig. 1,movement of plunger 25 is again experienced only so long as roller 22contacts with sloped surface 12 to thus produce downward movement ofplunger 25 during which fuel enters and fills the pumping chamber 39 viasupply pipe 34 as previously described. This may be better understood byreferring to the heavily dotted line 33 in Fig. 1 which indicates thepath taken by roller 22 as its link 21 is swung back and forth by crank19 with the various parts occupying the positions indicated.

I do not limit embodiment of my invention solely to the constructionherein illustrated, as it will be apparent to one skilled in the artthat analogous means, which, though not entirely desirable, may beemployed to achieve the novel principles of operation involved in myfuel pump. For example, interposer member 14 might be devoid ofdepressive and elevating adjustment through the vertical range 17 andinstead guiding member 9 could be adapted to effect such verticaladjusting movement with respect to 14, without departing from the broadscope of my invention.

What I claim is:

1. A fuel supplying and injection control system for an internalcombustion engine of the fuel injection type having a power piston andincluding fuel pumping means having a pumping plunger, a quantity offuel control for varying the quantity of fuel delivered per pumpingcycle, a time of injection commencement control for varying the time ofinjection commencement with respect to the position of the power pistonof the engine, a change of velocity control for changing the velocity atwhich fuel is delivered and injected by the pump, means related witheach control to provide for the adjustment of each control without anysubstantial change in ,the desired adjustment of the other controls, theaforementioned quantity control means comprising means for changing theamplitude of stroke of the pumping plunger while maintainingsubstantially unchanged the time of injection commencement and/or thevelocity of fuel injection by the plunger.

2. A fuel supplying and injection control system for internal combustionengines of the fuel injection type which employ a power piston andincluding in combination fuel pumping means which include a pumpingplunger, means for varying the quantity of oil fuel supplied per pumpingcycle of the plunger, said means comprising means for changing theamplitude of stroke of the pump plunger while maintaining substantiallyunchanged the velocity of fuel delivered by the pump and/or the time ofinjection commencement.

3. A fuel supplying and injection control system for internal combustionengines of the fuel injection type including .in combination with a fuelpumping plunger, of triple control means for changing the action of thepumping plunger itself, each control being operable independently of theother two controls. and being operable for adjustment while maintainingsubstantially unchanged the respective desired adjustments of the othercontrols.

4. The invention set forth in claim 3 in which one control includesmeans to effect a change in amplitude of stroke of the pumping plungerto change the quantity of fuel supplied per stroke while maintainingsubstantially unchanged the velocity at which fuel is delivered by theplunger when the quantity of fuel delivered by the plunger is varied bysaid means.

5. The invention set forth in claim 3 in which one control includesmeans to effect a change in amplitude of stroke of the pumping plungerto change the quantity of fuel delivered per stroke and in which anothercontrol includes means to change the velocity of movement of the pumpingplunger and in which the other control includes means to effect a changein the time of initiation of movement of the plunger.

6. Afuel supplying and injection control system for internal combustionengines of the fuel injection type which have a pumping plunger forinjecting the fuel and including devices for effecting control ofquantity of fuel-supply, velocity of fuel supply and timing of injectioncommencement wholly by the action of the pumping plunger itself, saiddevices including means for effecting substantially independently anyone of the aforesaid control adjustments of the action of the plungerwhile maintaining substantially unchanged the action of the plunger asregards the other. two adjustments.

7. A fuel supplying and injection control system for internal combustionengines of the fuel injection type which have a pumping plunger forinjecting the fuel and including device for effecting control ofquantity of fuel supply, velocity of fuel supply and timing of injectioncommencement wholly by the action of the pumping plunger itself, saiddevices including means for effecting substantially independently anytwo'of the aforesaid control adjustments of the action of the plungerwhile maintaining substantially unchanged the action of the plunger asregards the remaining adjustment.

8. A fuel injecting system including a pumping plunger, a link pivotallyconnected thereto, cranklike operating means for oscillating the link,and including in combination therewith a bearing member on the link anda guiding member adapted for cooperation therewith and having a radiusof concave curvature corresponding to the length of the link from itspoint 4 of pivotal connection with the plunger to the contacting pointbetween the bearing member on the link and the guiding member to providefor interruption of movement of the pumping plunger.

9. The invention set forth in claim 8 in which an adjustable linkdisplacing interposer member is provided which cooperates with thebearing member upon the link to displace it away from the guiding memberupon oscillation of the link.

10. The invention set forth in claim 8 in which an adjustable linkdisplacing interposer member is provided which cooperates with thebearing member upon the link to displace it away from the guiding memberupon oscillation of the link, and means cooperating with said interposermember for effecting a tilting displacement of the interposer member forthe purpose described.

11. The invention set forth in claim 8 in which an adjustable linkdisplacing interposer memher is provided which cooperates with thebearing member upon the link to displace it away from the guiding memberupon oscillation of the link, and means for effecting a displacement ofthe interposer member back or forth with respect to and substantially inthe plane of the direction of oscillation of the link.

12. The invention set forth in claim 8 in which an adjustable linkdisplacing interposer member is provided which cooperates with thebearing member upon the link to displace it away from the guiding memberupon oscillation of the link, and means for effecting a relative changeof level adjustment of the interposer member with respect to the guidingmember.

13. The invention set forth in claim 8 in which an adjustable linkdisplacing interposer member is provided which cooperates with thebearing member upon the link to displace it away from the guiding memberupon oscillation of the link, said interposer including a secondaryguiding portion which has the same radius of concave curvature as thatof the guiding member.

14. The invention set forth in claim 8 in which interposing means areprovided comprising an adjustable link displacing interposer member isprovided which cooperates with the bearing member upon the link todisplace it away from the guiding member upon oscillation of the link,said interposer means including a supplemental guiding portion which ispivotally mounted upon the interposer member and variably adjusted withrespect thereto by a compensating linkage so that the instantaneouscenter of curvature of the supplemental guiding portion is alwayslocated substantially on the path traversed by the reciprocating pointof pivotal connection between the link and pump plunger.

JOSEPH C. GEOFF.

